1. Field
Aspects of the present invention relate to a thin film deposition apparatus, and more particularly, to a thin film deposition apparatus capable of forming a precise pattern on a large substrate.
2. Description of the Related Art
Organic light-emitting display devices have a larger viewing angle, better contrast characteristics, and a faster response rate than other display devices, and thus have drawn attention as a next-generation display device. An organic light-emitting display device may generally generate visual light when holes and electrons respectively injected from an anode electrode and a cathode electrode are recombined in an organic emission layer and thus light is emitted. However, it is difficult to achieve high light-emission efficiency with such a structure. Thus, organic layers, including an electron injection layer, an electron transport layer, a hole transport layer, a hole injection layer, etc., together with the organic emission layer are optionally additionally interposed between the anode and cathode electrodes.
The anode and cathode electrodes, the organic emission layer, and the organic layers of the organic light-emitting display devices may be formed using a variety of methods, one of which is a deposition method. When an organic light-emitting display device is manufactured using the deposition method, a fine metal mask (FMM) having the same pattern as a thin film to be formed is disposed to closely contact a substrate on which the thin film is to be formed. A thin film material is deposited over the FMM in order to form the thin film having the desired pattern.
However, it is difficult to form fine patterns of organic thin films such as an organic emission layer or organic layers. The light emission efficiency of red, green, and blue colors may vary according to features such as the fine patterns and the thicknesses of the organic thin films. Thus, it is difficult to improve light emission characteristics of organic light-emitting display devices.
Also, recently, there is higher demand for large-sized display devices, but it is difficult to pattern organic thin films on a large surface using a conventional thin film deposition apparatus. Thus, it is difficult to manufacture large-sized organic light-emitting display devices having satisfactory levels of driving voltage, current density, brightness, color purity, light emission efficiency, durability, etc.